Method of and means for orienting tools in well bores



1943. L. c. MILLER 2,327,653 METHOD OF AND MEANS FOR ORIENTING TOOLS IN WELT: BORES Filed D90- 12, 1939 3 Sheets-Sheet l 3mm Leonidas C. M77/er 6 M y 2 f ug 4,19 3.- L.. MILLER 2,327, 58

METHOD OF AND MEANS FOR ORIENTING TOOLS I N WELL BORES Filled Dec. 12. 1959 s Sheets-Sheet 2 Illlllllllll Aug. 24, 1943. L. c. MILLER r 2,327,653

QETHOD OF AND MEANS FOR ORIENTING TOOLS IN WELL BQRES Filed Dec. 12, 1939 3 Sheets-Sheet 3 \(XQW Illlll) Leon/Has C. MIY/er Patented 24, 1943 rm'rnon or imp MEANS FOR oarnnrmc TOOLS IN WELL aortas Leonidas 0. Miller, Dallas, Tex asslgnor of onehalfto Eastman Oil Well Survey Company,

Dallas, Tex" a corporation of Delaware, and one-half to Eastman Oil Well Survey Comration, Long Beach, Calif., a corporation of Call- Application December 12, 1939, Serial No. 308,801

12 Claims. (01. ass-1.8)

This'invention relates to new and useful improvements in methods of and means for orienting tools in well bores. As'is well known, many wells, particularly those produced by rotary drilling, deviate very considerably from the vertical and'such deviation may cause the lower end of thebore to completely miss the oil-bearing locality or stratum. After deviation of the bore begins, little can be done to control the drilling from the surface so as to straighten said bore and, therefore, it has become the practice to insert a whipstock in said bore, said whipstock having an inclined guiding surface which directs the drill in a desired direction. Obviously, when a whipstock is employed, it is essential that said whipstock be properly oriented to assure that a proper correction of the direction of the bore hole will be made.

Whipstocks are not only employed in straightening well bores which have deviated from the vertical, but are also used in directing a bore position of the i601 within the bore; such information making possible the accurate rotation of the pipe to locate the tool in the desired azimuthal position.

I such as a whipstock,'within a well bore includhole in a predetermined direction, which practice is generally known as directional drilling. In directional drilling, the bore hole is started from An important object of the invention is to provide an improved orientation method which includes surveying the bore hole to determine the direction of inclination or deviation from the vertical of the bore, then lowering a tool to be oriented into the boreand recording the position of the tool relative to the azimuthal position of the 'low side of the bore hole, whereby such record. taken with the inclination or deviation previously obtained, indicates the azimuthal position of the tool within the bore. I

Another object of the invention is to provide an improved method for orienting a tool within a well bore, wherein the tool is secured to the lower end of a drill pipe in a known relation and is lowered into the bore, after which a recording instrument is lowered through the pipe to record the azimuthal position of the low side of the hole relative to the pipe and tool, whereby such record provides accurate information as to the azimuthal ing a sub adapted to be connected to a drill pipe and having a magnetic element mounted therein, together with a recording instrument having a position indicator arranged to co-act with the magneticelement so as to locate the indicator in a predetermined position within the sub, said instrument having means for recording the low side of the bore hole on said position indicator, whereby the low side of said hole with relation to the azimuthal position of the magnetic element in the sub may be determined; said sub having the tool to be oriented secured thereto in known relation to the magnetic element in said sub, thus permitting an accurate determination of the azimuthal position of the tool by a determination of,

the position of the magnetic element relative to the low side of the bore.

Another object of'the invention is to provide an improved apparatus, of the character dein a-well bore, wherein the recording instrument may be lowered and raised through the drill pipe on a wire line or cable and also wherein the indicator of the instrument is positioned within the drill pipe in a predetermined manner by means of co-acting magnetic elements, whereby the relation of the indicator to the pipe may be readily determined at the surface by means of a suitable reading device and also whereby the recording on said indicator, which recording is representative of the azimuthal position of the low side of the hole, may be determined in degrees from the azimuthal position of themagnetic element mounted in the drill pipe.

Still another object of the invention is to provide an improved reading device for use with an orienting apparatus, of the character described, which is constructed so that an instantaneous and accurate determination of the azimuthal position of the tool to be oriented in the bore, may be had.

' trating the reading device used with A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a readingof the following specification and byreferen'ce'to the accompanying drawings, in which an example of the invention is shown, and

wherein:

' Figure 1 is a view, partly in elevation and partly in section, illustrating a drill stem having a whipstock secured thereto and showing the im-- proved orienting apparatus, constructed in ac-. cordance with the invention in position within the drill stem,

Figure 2 is an enlarged, transverse, vertical sectional view of the orienting apparatus secured to the lower end of the drill stem,

Figure 3 is a horizontal, cross-sectional view, taken on the line 3-3 of Figure 2,

Figure 4 is a horizontal. cross-sectional view,-

taken on the line 4-4 of Figure 2,

Figure 5 is anenlarged transverse, vertical sectional view of the position indicator which is mounted within the apparatus,

. Figure 6 is a horizontal, cross-sectional view,

takenon the line 6-6 of Figure 5,

Figure 7 is a plan view or the reading device, Figure 8 is a view similar to Figure 7 and show ing the opposite side of said device, I Figure 9 is an enlarged, transverse, vertical tral portion of the reading device showing the indicator mounted therein, when a reading is taken;

Figure 12 is a horizontal, cross secti'onal view taken on the line |2-| 2 of Figure 9.

Figure 13 is a view partly in elevation and partly in section showing a slightly modified form of the invention,

Figure 14 is an enlarged, transverse, vertical sectional view of the modified structure,

Figure 15 is a horizontal, cross-sectional view,

' taken on the line l5'-| 5 of Figure 13,

- .Figure 16 is a horizontal, cross-sectional view, taken onthe line lS-lfi ofFigure 14,

Figure 17 is the view similar to Figure 7, illusof the invention, and

Figure 18 is a view similar to Figure 17. showing the underside of the reading device.

In carrying out the improved method, it is first necessary to make a directional survey of the bore hole at the point at which the tool is to be set. so as to determine the direction of inclination of the hole at such point. This may be done by any suitable instrument, either a gyroscopic or a magnetic instrument, and such instrument may be lowered into the drill stem on a wire line or cable for the purpose of making the initial survey. An instrument, which is generally known to the trade as a single shotsurveying instrument may be employed. By means of the instrument, the degree of inclination or deviation from the vertical, as well as the direction of such inclination, may be determined. For example,'the instrument may show that the bore hole inclines N. E., or it may show any other reading in accordance with the inclination and direction of the bore hole.

After this information is obtained by the initial directional survey of the bore hole by any this form.

collar [2.

suitable instrument, the'drillstem 10 (Figures 1 and 2) is lowered into the well bore A. In carrying out the invention, an elongate cylindrical sub I l, which is preferably constructed of 'a nonma netic material, is coupled to the lower end of the drill stem I0 by' means of a-Sllltable toupling The collar threads onto the lower end of the drill stem and is provided with a nipp 13 which is threaded into the upper enlarged end of the bore ll of the sub! A drill bit I5 is secured to the lowerend of the sub ll bein screw-threaded thereon and said bit may be of any suitable type, a drag bit being illustrated. With this arrangement, it will be obvious that the sub II is interposed between the lower end of the drill stemand the drill bit l5.

A whipstock H, or other tool to be oriented. is provided with the collar l8, which is preferably made integral with its upper end. This collar surrounds the drill bit l5 and is secured thereto by means of a shear pin l9. It is noted that the shear pin is preferably located in vertical alinement with the angular face Ila of the whipstock. When the drill stem is lowered through the well here A, it will be obvious that the whipstock, as well as the drill bit, are lowered therewith. A rotation of the drill stem will impart a rotation to the whipstock, whereby said whipstock will be oriented in the hole in the desired manner. After theshear pin has been broken, the drill bit [5, sub H and drill stem [0 may move downwardly through the collar l8 of the whipstock and upon such movement, the bit is guided by the angular face rm of said whipstock. It is noted that this construction, just described, is general practice and forms no part of the present invention.

.A pair of magnetic elements or bars 20 are mounted in the wall of the sub or sleeve H, such elements being preferably constructed of a magnetic material having a high coercive force, such as one of the aluminum-nickel-cobalt alloys. As is clearly shown in Figures 2 and 3, the magnets are disposed diametrically opposite each other within the sub and are located nearer the upper end thereof; Each magnet is axially mounted within a collar 2| which, is threaded into a radial opening 22 provided in the sub. 3

The collar is preferably constructed of a" nonmagnetic material and has the magnet pressed or otherwise secured therein. An external an- 5 nular flange 23 is formed on the collar and en- 1, gages within a recess in the wall of the sub to limit the inward'movement of the collar.

magnetic material; the body of the sub ll may be either nonmagnetic or magnetic, as desired. 1

A spider 24 is threaded into the extreme lower f end of the bore ll of the sub and is, of course, 5

provided with vertical ports 25 extending there- In i .this manner, each magnet is retained in position within the sub and yetmay be removed for replacement by merely unscrewing the collar i from the opening 22. By observing Figure 2, it will be seen that the inner end of the magnet 1 is exposed within the bore I4 of the sub. It is noted that since the collars 23 are of a nonthe magnetic elements 200. Of course, in making up the threads, when the drill bit I is secured to the sub, said pin is may become misalined with the magnetic elements in a vertical plane and in such instance, the number of degrees of such misalinement is recorded, whereby the operator knows at all times the relative position of the shear pin and the magnetic elements 29. Since the shear pin is disposed in the same vertical plane as the angular face I .of the 'whipstock, the operator is thus advised of 'the relative position of such angular face Ila sub ll immediately below one of the magnetic elements and this opening may receive the shear pin 19, in which case, the whipstock would be secured directly to the sub instead of to the drill bit. In this instance, the angular face Ila of said whipstock would at all times be alined in a vertical plane with the magnetic elements".

After the assembly, as above described, is lowered into the well bore A, a suitable recording instrument B is arranged to be lowered by means of a wire line or cable 28 downwardly through the drill stem and into the bore of the sub II. This instrument may be similar to the one which is fully disclosed in my co-pending application filed May 18, 1939, Serial No. 274,329. The instrument is housed within an elongate shell 29 which has its lower end closed, the upper end of said shell being also closed by a cable socket 30. A pair of coil springs. 3| are disposed at each end of the instrument B within the shell 29 so as to absorb shock as the instrument is lowered downwardly into position through the drill stem. The lower end of the shell 29'has a collar 32 secured thereon and this collar carries a disk 33, which is constructed oi. lead or other soft material. The disk 33 has a small opening at its center to permit equalization of pressures thereacross. When the deviceis lowered through the drill stem and into the bore "-0! the sub II, this lead disk 33 is adapted toeengage and be punctured by the pointed upper end of the axial pin 26 within the lower end of the bore l4, whereby the opening therein is enlarged. The pin not only serves to stop the shell 29 in its proper position within the sub, as will be explained, but aJso in puncturing the disk 33 to enlarge the small opening indicates tothe. operator, after the removal of the instrument, that said instrument was properly located within the sub. If desired, the lead disk could be omitted.

The instrument B includes an elongate casing or tubular housing 34 which has its upper end closed by a suitable cap member 35. An electric lamp 36 is mounted intermediate the ends of the housing 34 and is supplied with current by a dry cell battery or batteries 31 which are located within the housing between the lamp 3'8 and the cap 35. A suitable timing mechanism (not shown) is also mounted in the housing above the batteries 31 and such mechanism is arranged to close the electrical circuit to'the lamp 36 at a predetermined time. Such timing mechanism forms no. part of the present inventlon and any suitable mechanism which will close an electrical circuit, may be employed.

An elongate, tapered, or conical tube or plumb-* bob 33 is mounted within the housing 34 immediately below the electric lamp 36. The upper end of the tube or plumb-bob is enlarged and is gradually tapered or reduced at its lower end as is clearly shown in Figure 2. The upper end of the tube is mounted, by means of a cardan suspension 33, within an annular flange 40 which is provided within the housing 34. In this manner, the tube is mounted or suspended so as to undergo a universal movement within the housing 34 and, therefore, said housing may be inclined from the vertical and said tube will always remain in a vertical plane.

- A projection lens 4| is mounted in the reduced lower end of the tube or plumb-bob 38 and when the lamp 36 is illuminated, the 'lightrays pass downwardly through the tube 38 and are projected through the lens 4|. The projection lens acts to direct the light rays onto-the upper end of a position indicator disk 42, and this disk is isnounted within the lower portion of the housing The disk 42 is constructed of a suitable metal which is capable .of being magnetized and as is clearly shown in Figure 5, said disk is provided with a peripheral, up-turned flange 43. The disk is secured to the upper end of a stem or shaft 44 which extends downwardly through an axial bore 45 which is provided within a block or plug 46. The plug is screw-threaded into the lower end of the housing 34 and closes said lower end. The lower-end of the stem 44 is tapered or pointed and rests upon bearings 41 which are supported within a bearing race 48, the latter being insertable within a counterbore 49 of the plug. The hearing race 48 is held in position within the counterbore by a coil spring 50 which, in turn, is retained by a plug 5| which closes the lower end of said counterbore. Upper displacement of the stem and disk from within the bore 45 is preventedby a retaining screw 52 which is threaded radiallythrough the body of the plug or block 46. The inner end of the retaining, screw extends into the enlarged upper end- 4511 of the bore 45, said inner end being confined between the flanges 53 and a collar 54 which is secured to the upper end of the stem and on which the disk 42 is mounted. .For centering the stem 44 within the bore 45, a suitable bearing ring 55 is seated on the angular shoulder 53 which is formed between the bore 45 and the enlarged upper end 45a thereof.

Obviously, the metallic disk 42 is mounted to freely rotate within the lower portion of the housing 34 below the elongate tube or plumb-bob 38. The disk" is magnetized so as to be at tracted' by the magnetic elements 20, whereby when the disk is located opposite said elements,

the same is rotated to a predetermined relative position therein. In other words, the point N in Figure 6 on the disk will be attracted to one of the magnetic elements 20, while the point S, which is diametrically opposite the point N, will be attracted by the other element 20. Therefore, whenever the disk 42 is positioned opposite the magnetic elements 20, the disk will always assume the same relative position therein due to the attraction of the magnet to the magnetized material of the disk 42. r

The provision of the peripheral flange or lip 43 on the disk 42 .forms a recess in the top of said disk and this recess is arranged to receive a disk 51, which disk is preferably constructed of a photographic printing out proof paper. Of course; the invention is not to be limited to this particular type of paper, as any light sensitive paper or material, capable of being developed by exposure to light, may be employed. The center of this paper disk 51 represents the truevertical plane and when the elongate tube or plumb-bob 38 and the housing 34 are disposed in a true vertical plane, the light from the lamp 36 is directed exactly onto the center of the disk--51.

. When the tube 38 assumes a position at an angle with relation to the housing due to the inclination 'of the housing, thelight rays are directed onto the disk off-center of said disk, Manifestly, the difference between the center of the'disk and the housing inclines oil. of the verticaL.

When the disk is placed in position below the plumb-bob, the paper on which the disk is constructed is unexposed. When it is desired to take a reading, the circuit to the electric lamp 36 is closed to illuminate said lamp and the light rays from said lamp pass through the lens 4| and I 20 the electrical circuit to the lamp 36 to illuminate are concentrated at a given point onthe disk 51. If both the plumb-bob or tube 38 and the housing 'were in a true vertical position, the light beam would be concentrated on the center of disk 51. This beam striking the surface of the disk results in an exposure of said surface, which brings out a dot at the disk. The lamp 36 is illuminated for a suflicient length of time to expose or print out that portion of the disk on which the light beam is concentrated. If the outer housing 34 is at an inclination from the vertical, due to the inclination of the sub I I, it will be manifest that light beam from the lamp 36 will be directed onto a point which is oif-center of the disk 51. The position of the dot will, of course, be in accordance with the angle of inclination and said dot will be representative of the azimuthal position of the low side of the hole. It is noted that the dot is on that side of the disk opposite the direction of inclination of the bore hole, that is, if the hole inclines toward the north, the dot is formed 180 degrees on of north, or south. Thus, the dot is 180 degrees off of the true direction in which the bore hole inclines.

In carrying out the improved method, a directional survey ofthe bore holeA is first made at the point of setting of the tool by means of a suitable surveying instrument (not shown). As has been pointed out, a single-shot surveying instrument may be employed and it will be assumed thatsuch survey shows that the direction of inclination or deviation of the well bore at the point at which the tool is to be set is N. 45 W. After the above directional survey is completed, the

drill stem l0, having the sub ll, drill bit l5 and whipstock l1 secured thereto, is lowered through the well bore to the position at which it is desired to set the whip'stock. As has been pointed.

. out, the magnetic elements are mounted within As explained, the lower end of the shell 29, having the lead disk 33 thereon, strikes the axially disposed pin 26 within the lower end of the bore l4 of the sub. The pin serves to puncture or rupture the disk 33 and at the same time halts further downward movement of the shell and of theinstrument B. The length of the shell and the disposition of the indicating disk 12 therein is such that when the lower end of the shell v23 5 is resting on'the pin 26; said disk 421s located opposite the magnetic elements 20, as is clearly shown in'Figure 2-. The metallic disk 42, as has beenexplained, has the paper recording disk 61 mountedtherein. As soon as the disk 42 moves '10 opposite the magnetic element 20, said disk is the point at which the light rays focus thereon" 'is representative of the number, of degrees which attracted by the magnetic elements so as to position the disk with the point N adjacent one of the magnetic elements and the point S adjacent the other magnetic element. The direction of rotation'of the disk will depend upon the mag-' netism of the elements. After a predetermined l n th. of time, the timing mechanism within the upper portion of the housing 34, which mechanism has not been shown, automatically closes inclined from the vertical? the sub H, as well as the shell 29 within said sub, are also inclined from the vertical. Such inclination will have caused the plumb-bob or tube 38 to be inclined within, and relative to, the .wall of the housing 34 and shell 29, whereby the light rays passing through said plumb-bob are directed onto a point which is oiI-center of the disk 51.

The light rays striking the disk. 51 will result in a development of the particular point on which 5 they are concentrated and with the result thatv dot has been formed on the paper disk, it is manifest that said dot will be representative of the azimuthal position of the low side of the hole and will be exactly, 180 degrees from the direction in which the hole inclines. The instrument B is then removed from the bore of the sub and is pulled upwardly throughthe drillstem III by means of the cable 28.

. At the surface, the instrument B is removed from the shell 29, after which the plug or block 46, which is threaded intp the lower end of the housing'34 of the instrument, is removed therefrom. This block carries the disk 42 and removal of the plug results in a removal or the disk from the housing. After such removal, the plug is mounted in a reading device 60, wherein the relative position of the dot formed on the recordmg disk 51 with relation to the position of the whipstock, may be determined. The reading device may take various structural forms, but it 60 is preferable that the same be constructed as shown in Figures 9 to 12 of the drawings.

As illustrated, the reading device 60 includes a circular block or body 6| which is provided with 5 an axial threaded opening 62. The lower poru 0f the p ing 62 is enlarged to form an annular shoulder 63 and when the plug 46 is threaded into the opening 62, anexternal shoulder on said plug will abut the shoulder 63, as is clearly shown in Figure 9. When the plug is 5 75 pair of magnetic elements ZQa, which are conthreaded into the opening of the body 6|, the d1sks 42 and 51 are located within the enlarged threaded locking, screw 14,- which 2,327,658 7 strujcted in the-same manner as the :magnetic elements 20 within the sub H, are disposed therein. As is clearly shown in Figure 9, the magnetic elements 20a are located on opposite sides in opposed relation and are inhorizontal alinement with the metallic disk 42 Thus, when the plug 46 is mounted within the body 6|,the disk 42 is "disposed adjacent the magneticelements 20a,

whereby said elements serve'to move the disk 542 to exactly the same position that. said disk assumed within the sub due tothe attraction of the m netic elements 20; Thus, itmightbe said that'the magnetic elements -20a are. com-v parable with the magnetic elements 20 in the sub,

the sub being represented by the circularbody 6|.

Aring '66 enclosesthe peripheryvof thebody 6| and this rihgis formed with aninwardly directed, annular flange 61 at its, upper .end. The flange engages within a recess 66 formed'in the upper peripheral portion of the body 6|, whereby said ring is rotatably mounted or, supported on the-body.- As an additional support and guide for the ring 66, a pin 66 is threaded through the ring and has its inner end riding within an annular groove formed in the outer surface of the body 6| at the lower end thereof.

The ring 66 is representative of .the collar l8 on the whipstock l1 and said ring has a suitable mark M (Figures 7 and 8) which mark is representative of the angular face Ila or said whipstock. Since the body 6| netic elements a, is representative of the sub II "and the ring 66, which carries the mark M isrepresentative of the ring l6, it is manifest that the relative-positions of the'sub and the whipstock maybe indicated by rotating the ring around the body. The underside of the body 6| carries a suitable dial II which has graduations thereon, such graduations indicating degrees from zero to 180. The zero indication is opposite one of the magnetic elements 20a,:while the 180 lndication'is alined with the other magnetic element. It the face Ila of-the whipstock is in the same vertical plane as one of the magnetic elements 20 in the sub, the ring is rotated with relation to the body so as to align the mark M with the magnetic element 20:; which is representative or the element 20 with which the whipstock is alined. As illustrated, the mark is alined with the element 20a. carrying the zero indication (Figure 8). For locking the body 6| to the ring 66 to prevent rotation of the parts after the setting has been made, a friction look pin 12 is provided. This pin (Figure 10) is mounted within a lateral recess 13 formed in the body 6| and has its inner end beveled. This beveled endis adapted to be engaged by the beveled inner end of a I extends upwardly through a suitable opening 14a provided in the body 6|. The outerend of screw I4. It is manifest that when the screw H is rotated to move the same inwa i the beveled inner end of said screw coacts with the beveled inner end of the locking pin 12, to move said pin outwardly into engagement with the inner surface of the ring 66. By tightening the screw H, a frictional engagement between the pin I2 and the ring 66 is set up, whereby rotation of said ring relative to the, body 6| cannot be accomplished. V

A dial ring 15 overlies the upper surface of the body and is mounted .Within a suitable recess. prowhich carries the mag-,

the screw has a suitable head 16 made integral therewith, whereby the operator may readily rotate the placement by an annular flange 16 which is iormed'on a. collar 11. The-collar I'l is rotatably mounted within the upper end 64 of thelcentral opening of the body GI and said collafcarrles a end of the line 6|, so that the line terminates adjacent the dial ring 15. The-dial ringv is marked ofl and carries the four points of the compass north, east, south and west. The spaces between each compass point are graduated or divided into degrees.

I In using the reading device, the body 6| is Lfirst adjusted relative to the ring 66, whereby the magnets 200 within the body are alined with the circular body6| represents the sub while the mark M on the ring. As has been explained,

the mark on the ring 66 represents the tool or whipstock II which is to be set'. As shown in Figure l, the angular face lla of the tool is alined with one of the magnets 26in the sub and,

- therefore, one of the magnets withinthe body 6| is alined with the mark M on the ring 66 of the reading device. After such adjustment, the

inal directional survey of locking screw I6 is moved inwardly so as to frictionally lock the body 6| tothe ring to prevent accidental disarrangement of these parts.

After the reading has been taken within the sub, the instrument Bis disassembled by removing the plug 46 from the lower end thereof and screwing said plug into the opening 62 within the body 6|. This disposes the recording disk 51, on which the dot representative of the azi- -muthal position of the low side of the hole is dis played, below the lens 16; The lens and collar II which carries said lens, are then rotated so as to accurately align the dot with the hairline 8| on said lens. Manifestly, this .disk 51 assumes the same relative position within the body 6| that said diskassumes within-the sub because of the magnetic elements 20a which. are disposed within the body in the same manner-asthe'magnetic elements 20 located within the sub. The position of the magnetic elements with relation to the tool is, of course, known and hasbeen prearranged by the adjustment of the body 6| relative to the ring 66. By noting thefnumber of degrees between the hairline and the mark M on the ring 66, the exact number of degrees between the position of the tool and the azimuthal position of the low side of the hole may be determined. The indicator line 8|! which is degrees from theouter extremity of the hairline, or opposite the dot which represents the low which the hole inclines.

As has been explained, assuming that the origthe bore hole A indicated the inclination at said hole as being N. 45

W., then the dial ring 15 is rotated to align the point N. 45 W. with the indicator line 8|'.- The hairline 8| is of course, in vertical alin ment side of the hole, is indicative of the direction in vided therefor. Said dial ringisrotatable'within the'recess and is confined against upward dis- 6 with the dot on the recording disk 51. This indicates that the hole inclines in a direction N, 45 W.

and then; by taking the reading opposite the toolmark M, the exact azimuthal position of the tool is indicated. As shown in Figure-7, the position of the tool in this case is N. 60 E. If this is the: position at which the setting of said tool is to be made, no further step need be taken. Howthe reading device, obviates the necessity of any calculation as the dial I givesan accurate visual indication of the exact azimuthal position of the tool. The term azimuth" or azimuthal position" has acquired in oil well surveying a very broad meaning, the same as has the term orienting, which originally meant turning to the east, but now is accepted as meaning turning in any direction. Azimuth is used in oil well surveying to designate substantially any angular direction from a particular point. It is noted that the reading device simulates the various elements which are located within the well bore and the provision of the magnets makes possible the movement or positioning of the indicator disk to the exact relative position within the reading device as said disk assumes within thebore of the sub Ii. Itis pointed out that if the'well tool is not in the same vertical plane as the magnets 20 within the sub, then the difference in degrees between the position of said tool and one of the magnetic elements 20 is compensated by a relative rotation of the ring 66 on the body 6|. In other words, if the tool is located 30 degrees out of alinement with one of the magnetic elements 20 in a vertical plane, then the line M on the I ring 664s disposed 30 degrees from the magnet having the indication zero in alinement therewith. In such case, the body and ring would, of course, be locked in the correct position in the same manner as has been explained. Although a particular reading device for carrying out the purpose of the invention has been disclosed, it is manifest that various types of devices for accomplishing the results could be devised and the invention is not to be limited to' the particular construction details of the reading device described. The invention has been described as being employed for setting a whipstock within the well bore, but, obviously, it could be employed for orienting any other tool or device, such as a coring device, knuckle Joint or deflecting tool.. The illumination of the lamp 36 within the instrument B has been described as controlled by suitable timing mechanism (not shown) within said instrument but any suitable switch arrangement, either manually or automatically operated, could be used without departin'g fromthe invention "In Figures 1 to 12, a pair of magnetic elements 20 have been shown and described as co-acting with the magnetized-indicating disk 42. How-, ever, it would. be possible to omit one of the elements 20, in which case only a single magnet would be depended upon to rotate the indicating element to its predetermined position within the is employed, only a single magnet would be provided in the reading device 60.

' It is not always necessary to employ a magnetized indicating disk 42. In Figures 13 to 18; a slightly modified form of the invention is shown. In this form a single magnet 90 is mounted in the sub ll, being substituted for the magnets 20.

The magnet 90 may be of any suitable construction and could be a duplicate of one of the magnets 20. The magneticdisk 42 is eliminated and in place thereof a nonmagnetic disk Si is substituted therefor. The disk 9| is mounted in substantially the same manner as the disk 42 and is preferably constructed of brass, or other nonmagnetic material, An insert 92 is mounted at one side of the nonmagnetic disk 9| and this insert is of a material which is capable of attraction by the magnet 90; such a material would be soft steel.

when the disk 9| is lowered into the bore of the sub along with the instrument B, it will be manifest that the magnet 90 will attract the steel insert 92, whereby the disk is rotated so that said insert is adjacent the magnet, as is clearly sub. In the case where only the single magnet within the bore of the sub ll.

shown in Figure 16. Thus, the disk will always be caused to assume a predetermined position The disk 9! carries the recording disk 51, which is constructed of the-printingout paper andthe operation of this form is substantially the same as the first form hereinbefore described.

When the single magnet shown in Figures 13 and 14 is used, together with the nonmagnetic disk 9|, the reading device 60a is substituted for the reading device 60, shown in Figures 9 to.11. The device 600 is substantially the same in construction as the device 60 with the exception that only a single magnet a. is provided. The adjustment of the reading device is made in exactly The magnets 20 and 90 have been, illustrated as I mounted in a special sub II, which is interposed between the drill stem HI and the drill bit l5. It is particularly pointed out that the invention is not to be limited to the use of the sub I l, as said magnets could be mounted either in the drill stem ID or in the body of the drill bit l5. In such case, the instrument B would be moved into position opposite the magnets and the operation would be the same.

The foregoing description of the invention is explanatory thereof andvarious changes in the size, shape and materials, as well as -in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

1. The method of orienting a tool within a well bore including, lowering the tool into. the bore on a hollow drill stem which drill stem carries a magnet, lowering within the drill stem an instru ment having an indicating element which is arranged to co-act with the magnet so as to assume a predetermined position with relation the stem, recording on the element the angular position of the low side of the bore relative to the stem, withdrawing the instrument from the drill stem, causing the recording element to assume the same relative position within a readingdevice as said element had assumed within the drill stem, said device having an indication representative of the position of the tool, determining the difference between the position of the low 7 ing index means movable with said movable means, together with means responsive to a. deflection of said instrument to the vertical tor making an index on said index means, then making an index on said index means, then withdrawing the instrument from the well bore, then causing the movable means to assume a location simulating the location of said means with re-' spect to the tool, then determining the degree through the drill stem and adapted to occupy a predetermined final longitudinal position therein, said instrument containing a rotatable indicating element and means for recording the inclination of the instrument from the vertical to indicate and record the position of the low side of the hole on said element, and magnetic means mounted in the drill stem and co-acting with the indicating element to rotate said element to a predetermined position relative to the stem, whereby the indication of the position of the low side of the hole is recorded relative to the drill stem and tool carried thereby.

3. In combination, a hollow drill stem, a tool carried by the drill stem and disposed in a predetermined position in a vertical plane relative thereto, an instrumentarranged to'be lowered through the drill stem and adapted to occupy a predetermined final longitudinal position therein, said instrument containing a rotatable indicating element having a light sensitive medium thereon, a plumb bob above the medium and means for directing light rays through the plumb bob onto the medium and thereby develop a portion of the medium in accordance with the position of the plumb bob, whereby such developed portion of said medium indicates the angular position of the low side of the'bore hole, and magnetic means mounted in the drill stem and co-acting with the indicating element to rotate said element to a predetermined position relative to the stem, whereby the indication of the angular position oi the low side of the hole is recorded relative to the drill stem and tool carried thereby.

4. The method of orienting a tool within a well bore which includes lowering into the well bore the tool to be oriented which is provided with a tubular stem having a locating element, then lowering into said stem an instrument having therein a movable indicating element and provided with means for making an index and means for locating the index, locting said movable indicator with respect to said locating element, then making an index on said indicating element, then withdrawing the instrument from the well bore and causing said indicating element to assume the same relative position with a location element as it did in the well bore, then determining with respect to the locating element and the index the degree of orientation necessary for of variance between said assumedlocation and the index, and then rotating said tool in accordance with the ascertained information.

' 6. The method of orienting a tool in a well bore which includes, lowering into the well bore a tool having a hollow stem provided with a magnet, lowering into the stem an instrument having a rotatable support subject to being magnetically positioned when brought into the field of said magnet and carrying an index medium, said instrument, also having means for making an index on said medium disposed to assume a position with respect to the low side of the bore, arresting said instrument in s'uch position as to cause the magnet to position the rotatable support and its index medium, making an index on said medium with respect to the low side or the bore and located with respect to the magnet, then withdrawing said instrument from the well "bore, magnetically positioning the support and its medium to locate the index with respect to a known point, then calculating in degrees the amplitude of rotation necessary to orient the tool, then rotating the tool in accordance with the ascertained information.

7. The method of orienting a tool within a well bore, which includes, a string including a tubular stem having a locating element and having a tool attached thereto, recording the degree of variation between the direction in which the tool faces and the locating element on a reading instrument, lowering said string into the well bore, then lowering into the tubular stem an instrument having means for making an index with respect to said locating element and the low side of the inclination of said well bore, then making an index, then withdrawing said instrument from the well bore, then placing said index means in the reading instrument which has a locating element and compensating means to set up the degree or variation between the direction of the tool and the locating element or the tubular stem, said second instrument also having markings representative of degrees, setting the reading instrument to position the locating element theme! in accordance with the previously made record of variance, then determining the degrees of orientation necessary to position the tooL-and then rotating the drill stem in accordance with ascertained information.

rotating the tool, and then rotating the stem in a location with respect to said tool and also hav- 8. A well surveying. instrument including, a casing, a rotatable support in said casing, means on the support for transversely carrying a removable index medium, means for making an index mounted to suspend above said medium on an axis constant to the vertical when said casing is deflected from the vertical, and means for causing said suspended means to make an index on said medium after a predetermined lapse of time, a casing within which the instrument is arranged to be inserted, and means carried by said casing co-acting with the rotatable support for holding said support stationary while said index is being made. a

9. In combination, a hollow drill stem, a tool carried by the drill stem and disposed in a predetermined position in a vertical plane relative .thereto, an instrument arranged to be lowered ment is rotated to a predetermined position relative to the stem so that the indication of the angular position of the low side of the hole is recorded relative to the drill stem and tool carried thereby.

' 10. In a well survey apparatus the combination of, a tubular stem adapted to be located in a well and having a locating element in its bore, an impaling member in the bore of said stem below said locating element, an instrument adapted to be lowered into the stem having an index member for coacting with said locating element, and a medium carried on the lower end of the instrument positioned to be impaled on said member when the instrument is lowered into the stem to cause the instrument to be sustained with its index member substantially opposite the locating element and to record by the impaling thereof the desired positioning oi said instrument.

11. In a well survey apparatus the combination of. a tubular stem adapted to be disposed in a well and having a locating element in its bore,

marking means in the bore of the stem below the locating element, an instrument adapted to be lowered into the stem having an index member for co-acting with the locating element, and additional marking means mounted on the lower end of the instrument co-acting with the markin means when the instrument is lowered into the stem to cause the instrument to be sustained with its index member in proper position relative to the locating element and to record the desired positioning of the element.

12. In combination, a hollow drill stem, a tool carried by the drill stem anddisposed in a P determined position in a vertical plane relative thereto, an instrument arranged to be lowered through thedrill stem and adapted to occupy a predetermined final longitudinal position therein, said instrument containing a recording element movable independently of the instrument and means for recording the inclination of the instrument from the vertical to indicate and record the position of the low side of the well bore on said element, and means mounted in the drill stem and co-acting with therecording element to cause said element to assume a predetermined position within the stem, whereby the position of the low side of the bore is recorded relative to the drill stem and the tool carried thereby.

LEONIDAS MILLER. 

